HP Pavilion a6400f Desktop (2.2GHz Intel Pentium Dual-Core E2200, 3GB DDR2, 500GB, DVDRW DL, Windows Vista Home Premium)

Compact Case Is Designed for Smaller Work Areas

This compact computer is smaller than the standard and midsize tower PCs that fit under your desk, making it ideal for limited work areas. Small case designs vary, too. However, such PCs tend to be underpowered (especially on gaming), and mini cases also have few available expansion slots and drive bays. Generally you'll have to expand the system via USB, FireWire, or eSATA peripherals, so make sure your compact system has a large number (and assortment) of ports.

Older-Generation Pentium CPU Is Adequate

This system is based on one of Intel's older Pentium processors, and though the chip's performance will be more than adequate in most cases, generally it won't be on a par with Intel's newer Core 2 or AMD's Phenom CPUs.

Earlier versions won't run 64-bit operating systems. Other drawbacks include the fact that original Pentium 4-based computers used RDRAM, which is harder to come by these days. The CPU line also lacks the advanced power-saving features found in newer processors.

We recommend opting for a newer processor if you're buying a new computer, but there's no compelling reason to upgrade an existing system if it has one of the faster Pentiums on board.

Good Amount of RAM for Running Multiple Apps at Once

This computer includes between 1GB and 3GB of RAM, our recommended level for a new PC. This much memory lets you run any modern operating system and comfortably work with quite a few applications open. The more installed memory your PC has, the more programs you can run smoothly at once, and the better the system will perform. Upgrading memory in a desktop after you purchase the PC is a breeze, but usually it's worthwhile to buy the amount of memory you want preinstalled with the system.

To use more than 4GB of memory on your PC, you need the 64-bit version of Windows XP or Windows Vista. The PCs that you see equipped with 3GB of memory (instead of 4GB) tend to use the 32-bit versions of Windows that are limited to 4GB of addressable memory, the top portion of which is addressed by the various hardware devices on the system. 

Adequate Hard-Disk Capacity for Business or Light Home Use

With respect to hard-drive space, this system is in the low-to-midrange tier. Whether that's important depends on your needs. Though video gobbles up drive space at a prodigious rate, most other data types take up far less than 500GB.

For basic business purposes or light home use, even 80GB or 120GB might be enough. A better minimum is 300GB, especially if you download movies or music. Compact desktops that use smaller, 2.5-inch laptop drives offer less capacity. In that kind of setup, 120GB is a more realistic minimum, though 80GB will be enough for most users.

Included Disc Writer Burns CDs and DVDs

The DVD burner on this system will allow you to burn CDs and DVDs (including movies, with the right software), play DVD movies, install software from CDs and DVDs, and play audio CDs and other types of discs. Most DVD burners have a slide-out media tray, though you'll find some slot-loading models on smaller or more-stylish PCs. Half-height drives exist, too; you'll find them mostly in laptops or external boxes. Since DVD burners are now a commodity item, even entry-level models are fast.

Integrated Intel Graphics Chip Can Handle Everyday Computing

This system uses a video chip from the leading graphics-processor manufacturer in the world: Intel. Though nVidia and ATI enjoy all the press, Intel has the biggest graphics market share because it supplies the integrated graphics chips for a huge number of desktop computers. For everyday computing, the performance of an Intel GPU is excellent. Unfortunately, by current standards the gaming performance is pathetic--largely because these chips usually use system memory instead of faster dedicated graphics memory.

With this PC, stick to business or general-application home use. And since only the most recent Intel GPUs can drive large wide-screen displays at their full resolution, be sure to check the chip-specific specs.

Windows Vista: Good Multimedia and Security, but a Resource Hog

This computer ships with Microsoft's latest operating system. Windows Vista offers improved multimedia and networking savvy, looks better than Windows XP, and has greater security than its predecessor, but it can be a slower-feeling operating system due to heavier resource requirements. You can run it with only 512MB of main memory in your PC, but having at least 1GB will provide a much better experience.

Common 32-bit versions of Windows Vista can address no more than 4GB of RAM, even if your machine has more available. So unless you're using the 64-bit version of Vista (or 64-bit XP, if you can still find a copy), a computer with 2GB to 4GB of memory is the right target.

FireWire Port Allows Rapid Data Transfer

The FireWire connection (also called an IEEE1394 or i.Link port) in this computer can rapidly transfer data to and from a range of devices, most commonly video cameras, external hard drives, and advanced sound cards.

Generally desktop PCs have a full-size six-pin FireWire port on the rear, often on a front panel. Some also include the smaller, unpowered four-pin connection that you can find on laptops and certain consumer electronics devices. (Camcorder makers often bundle a six-pin-to-four-pin FireWire cable because of this.)

The newer FireWire 800 (IEEE1394c) implementation is not backward-compatible and uses a nine-pin connector. If your peripheral (such as a video camera or external hard drive) uses FireWire 800, you should double-check to confirm that every desktop PC you're considering supports it, too. 

USB Connections Let You Connect Various Peripherals

USB (Universal Serial Bus) ports allow this system to use any number of USB peripherals such as printers, keyboards, and mice. You can also use an external USB hard disk or a USB thumb drive to expand this desktop's storage or back up your data.

Note that the older, much slower (11 megabits per second) 1.x implementation of USB was fine for peripherals, but is frustratingly slow for storage. New desktop computers all support the speedier USB 2.0 (480 mbps)--but double-check on that if you're buying a used or older system. And when it comes to USB ports, the more the merrier.

Card Reader Takes MultiMediaCard

This system's MMC slot allows it to read the older MultiMediaCard format--the predecessor of SD Card media. SD and SDHC slots will read MMC, too, but not vice versa. For the most part, MMC is simply an additional spec for an SD or SDHC slot, which will read the two (or three) types.

Card Reader Accepts Sony Memory Stick

This computer can read and write to Sony's proprietary Memory Stick flash memory devices, and with an adapter it could also support variants such as Memory Stick Pro, Duo, Pro Duo, and Micro. Few non-Sony devices use Memory Stick; however, the company is so large that chances are you might need to read data from one someday. Most times, Memory Stick is just one among several media card types that a desktop PC can accept.

Media Reader Takes SD Card

Equipped with an SD Card (Secure Digital) reader, this PC can transfer photos from a digital camera when you have no cable. With the proper adapter, SD slots will also read data from the miniSD media used in cell phones.

The newer SDHC (Secure Digital High Capacity) standard is not backward-compatible, so the slot may not read such cards; check the PC's specs further to determine whether it offers SDHC support. The latest SD variant, the microSDHC, is the tiniest flash memory card to date, measuring only 11mm across. It's also the fastest and roomiest, capable of holding up to 16GB of data.

Media Reader Takes CompactFlash Cards

This PC has a multiformat card reader capable of reading CompactFlash (also known as CF) cards. Despite having been supplanted by SD Card and SDHC, CompactFlash cards are still used in older digital cameras.